Primates were a type of species common among the worlds known to the Compact. Originally referring to Homo sapiens, apes, monkeys, yetis, and related species on Earth, the term came to refer to any alien species with the following characteristics:
- Warm-blooded
- Bears live young
- Breathes primarily oxygen
- Bipedal with four limbs ending in three-seven digits
- Sapient
- Capable of speech and written language